P-type Doping of SIC by Aluminum Implantation for Advanced Device Applications

1995 ◽  
Vol 410 ◽  
Author(s):  
Maria A. Caleca ◽  
Honghua Du ◽  
Joseph R. Flemish ◽  
Stephen P. Withrow
Keyword(s):  
Dopant Concentration ◽  
Dopant Activation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Aluminum Implantation ◽  
Device Applications ◽  
P Type ◽  
Type Conduction ◽  
Annealing Method

ABSTRACT6H-SiC epitaxial layers with a background n-type dopant concentration of 1 × 1016/cm3 were hot implanted to doses ranging from 4.0 × 1013 to 1.8 × 1014 Al ions/cm2 at 65, 135, and 220 keV to achieve a box-type implant distribution to a depth of 300 nm. Electrical activation of dopants was carried out using a proximity annealing method at 1500°C in a buffer environment to retard surface degradation of the SiC samples. Measurements using atomic force microscopy illustrated the morphological stability of the SiC surface during the high-temperature annealing. Transmission line measurements showed some degree of dopant activation. Characterization of fabricated p-n junction diodes demonstrated p-type conduction in the aluminum-implanted SiC samples.

Graphene growth on SiC and other substrates using carbon sources

2011 ◽  
Vol 1284 ◽  
Author(s):  
W. C. Mitchel ◽  
J. H. Park ◽  
Howard E. Smith ◽  
L. Grazulis ◽  
S. Mou ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Flux ◽  
Carbon Sources ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Films ◽  
Additional Control ◽  
P Type ◽  
Type Conduction

ABSTRACTDirect deposition of graphene from carbon sources on foreign substrates without the use of metal catalysts is shown to be an effective process with several advantages over other growth techniques. Carbon source molecular beam epitaxy (CMBE) in particular provides an additional control parameter in carbon flux and enables growth on substrates other than SiC, including oxidized Si and sapphire. CMBE using thermally evaporated C60 and a heated graphite filament on SiC is reported here. The graphene films were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy and Hall effect. Graphene films on Si-face SiC grown using the C60 source have Bernal-like stacking and n-type conduction while those grown using the graphite filament have turbostratic stacking and p-type conduction. The sheet concentration for both n- and p-type doping is linearly dependent on film thickness.

scholarly journals Analysis, Synthesis and Characterization of Thin Films of a-Si:H (n-type and p-type) Deposited by PECVD for Solar Cell Applications

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6349
Author(s):  
Abel Garcia-Barrientos ◽  
Jose Luis Bernal-Ponce ◽  
Jairo Plaza-Castillo ◽  
Alberto Cuevas-Salgado ◽  
Ariosto Medina-Flores ◽  
...  
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Optical Band Gap ◽  
Synthesis And Characterization ◽  
Force Microscopy ◽  
The Third ◽  
Atomic Force ◽  
Uv Visible ◽  
P Type

In this paper, the analysis, synthesis and characterization of thin films of a-Si:H deposited by PECVD were carried out. Three types of films were deposited: In the first series (00 process), an intrinsic a-Si:H film was doped. In the second series (A1–A5 process), n-type samples were doped, and to carry this out, a gas mixture of silane (SiH4), dihydrogen (H2) and phosphine (PH3) was used. In the third series (B1–B5 process), p-type samples were doped using a mixture of silane (SiH4), dihydrogen (H2) and diborane (B2H6). The films’ surface morphology was characterized by atomic force microscopy (AFM), while the analysis of the films was performed by scanning electron microscopy (SEM), and UV–visible ellipsometry was used to obtain the optical band gap and film thickness. According to the results of the present study, it can be concluded that the best conditions can be obtained when the flow of dopant gases (phosphine or diborane) increases, as seen in the conductivity graphs, where the films with the highest flow of dopant gas reached the highest conductivities compared to the minimum required for materials made of a-Si:H silicon for high-quality solar cells. It can be concluded from the results that the magnitude of the conductivity, which increased by several orders, represents an important result, since we could improve the efficiency of solar cells based on a-Si:H.

Dual Quantum Dot Superlattice

2018 ◽  
Vol 27 (01n02) ◽  
pp. 1840003
Author(s):  
Barath Parthasarathy ◽  
Pial Mirdha ◽  
Jun Kondo ◽  
Faquir Jain
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Field Effect Transistor ◽  
Crystalline Silicon ◽  
Force Microscopy ◽  
Atomic Force ◽  
Effect Transistor ◽  
P Type ◽  
Dual Quantum

In this paper, we propose a structure using four layers of quantum dots on crystalline silicon. The quantum dots site-specifically self-assembled in the p-type material due to the electrostatic attraction. This quantum dot super lattice (QDSL) structure will be constructed using a mixed layer of Germanium (Ge) and Silicon (Si) dots. Atomic Force Microscopy results will show the accurate stack height formed from individual and multi stacked layers. This is the first novel characterization of 4 layers of 2 separate self assemblies. This was also applied to a quantum dot gate field effect transistor (QDG-FET).

Synthesis and Characterization of Semiconductor Composites Gas Sensors Based on ZnO Doped TiO2 Thin Films by Laser-Induced Plasma

2021 ◽  
Vol 900 ◽  
pp. 112-120
Author(s):  
Souad G. Khalil ◽  
Mahdi M. Mutter
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Electrical Characterization ◽  
X Ray Diffraction ◽  
Type Conductivity ◽  
Force Microscopy ◽  
Atomic Force ◽  
P Type

This work presents the development of n-type (TiO2) and p-type (ZnO) gas-sensitive materials from ZnO doped TiO2 thin films prepared by pulsed laser deposition technique (PLD) on a glass substrate as a gas sensor of CO2 gas. TiO2 gas-sensing layers have been deposited over a range of ZnO content (0, 20, and 40) wt %. The obtained thin films analysis by atomic force microscopy (AFM), and X-ray diffraction (XRD). Electrical characterization shows that TiO2:ZnO thin films were p-type conductivity and ZnO added was unable to change the composition to the n-type conductivity. There are notable gas-sensing response differences between n-type and p-type ZnO doped TiO2 thin film. The responses toward all tested oxidizing gases tend to increase with operating temperature for the n-type TiO2 films. Besides, the p-type ZnO doping results in a significant response improvement toward tested oxidizing gases such as CO2 gas at the low operating temperature of 60 °C.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

Stereometric characterization of Dinizia excelsa Ducke wood from Amazon rainforest using atomic force microscopy

2021 ◽  
Author(s):  
Willian Silva Conceição ◽  
Ştefan Ţălu ◽  
Robert Saraiva Matos ◽  
Glenda Quaresma Ramos ◽  
Fidel Guereiro Zayas ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Amazon Rainforest ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dinizia Excelsa

scholarly journals A Universal Model for the Log-Normal Distribution of Elasticity in Polymeric Gels and Its Relevance to Mechanical Signature of Biological Tissues

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 64
Author(s):  
Arnaud Millet
Keyword(s):  
Elastic Modulus ◽  
Normal Distribution ◽  
Biological Tissues ◽  
Force Microscopy ◽  
Polymeric Gels ◽  
Atomic Force ◽  
Clear Explanation ◽  
Log Normal ◽  
Log Normal Distribution

The mechanosensitivity of cells has recently been identified as a process that could greatly influence a cell’s fate. To understand the interaction between cells and their surrounding extracellular matrix, the characterization of the mechanical properties of natural polymeric gels is needed. Atomic force microscopy (AFM) is one of the leading tools used to characterize mechanically biological tissues. It appears that the elasticity (elastic modulus) values obtained by AFM presents a log-normal distribution. Despite its ubiquity, the log-normal distribution concerning the elastic modulus of biological tissues does not have a clear explanation. In this paper, we propose a physical mechanism based on the weak universality of critical exponents in the percolation process leading to gelation. Following this, we discuss the relevance of this model for mechanical signatures of biological tissues.

In Situ Characterization of the Mechanical Behavior of Gecko's Spatulae by Atomic Force Microscopy

2013 ◽  
Vol 22 ◽  
pp. 85-93
Author(s):  
Shuang Yi Liu ◽  
Min Min Tang ◽  
Ai Kah Soh ◽  
Liang Hong
Keyword(s):  
Mechanical Behavior ◽  
Hierarchical Level ◽  
Intrinsic Properties ◽  
In Situ Characterization ◽  
Force Microscopy ◽  
Atomic Force ◽  
Theoretical Predictions ◽  
Multi Mode

In-situ characterization of the mechanical behavior of geckos spatula has been carried out in detail using multi-mode AFM system. Combining successful application of a novel AFM mode, i.e. Harmonix microscopy, the more detail elastic properties of spatula is brought to light. The results obtained show the variation of the mechanical properties on the hierarchical level of a seta, even for the different locations, pad and stalk of the spatula. A model, which has been validated using the existing experimental data and phenomena as well as theoretical predictions for geckos adhesion, crawling and self-cleaning of spatulae, is proposed in this paper. Through contrast of adhesive and craw ability of the gecko on the surfaces with different surface roughness, and measurement of the surface adhesive behaviors of Teflon, the most effective adhesion of the gecko is more dependent on the intrinsic properties of the surface which is adhered.

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